The invention relates to a system on a bookbinding machine, for permitting actuator-effected positioning of machine elements for book block format changing, or for format changing when processing other products of a similar nature.
In the pursuit of production efficiencies in bookbinding operations, particular significance has recently been attached to shortening setting and change-over times. In cases involving such complicated machinery as bookbinding machines, book block format changes call for the expenditure of comparatively large amounts of time, especially if measured in terms of production time. Adjusting systems have already come into use in various industries which function in a purely numerical manner. A particular problem arising in the case of bookbinding machines, however, is the further need to determine numerous setting points which are effected by compression of the book block.
In a known measuring system, a sample book block is placed in a measuring station in order to determine both the distance between the transport chains and the compressive force needed to hold the book block between them, this measuring station being located at some distance from the machine elements that are to be positioned. Thereafter, the sample book block is fed to a further measuring station, where the distance between the press plates belonging to the rounding and backing press station is determined, as well as the compressive force needed to hold the book block, this force having to exceed the one exerted between the transport chains, as is well known. With this known system, the machine operator determines the compressive force appropriate in each particular case, as a measured value which is a function of both displacement and pressure--doing so purely manually and without any precise advance information--and this measured value is input to a microprocessor in which it is evaluated as an actual displacement value, and stored as a required value.
Apart from the fact that skilled, experienced operators, and only such, are required for performing the determination of the measured value, this procedure invariably necessitates a readjustment operation. Owing to the fact that it has two separate measuring stations, the known measuring system is relatively expensive to build and, regarded as a whole, is exceptionally time-consuming to operate, since this has to be done manually and at the same time involves an unavoidable readjustment operation.